xref: /openbsd-src/lib/libc/arch/amd64/gen/isinfl.c (revision 4914100a9a976afb8e70010709918b347d2eae89)

/*	$OpenBSD: isinfl.c,v 1.2 2008/12/09 19:52:33 martynas Exp $	*/
/*
 * Copyright (c) 2008 Martynas Venckus <martynas@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <machine/ieee.h>
#include <math.h>

int
__isinfl(long double e)
{
	struct ieee_ext *p = (struct ieee_ext *)&e;

	p->ext_frach &= ~0x80000000;	/* clear normalization bit */

	return (p->ext_exp == EXT_EXP_INFNAN &&
	    p->ext_frach == 0 && p->ext_fracl == 0);
}